Fixed: README.md (bevyengine#9994)

# Objective

fixed readme.md.

## Solution

removed 'iOS cron CI' badge as its source
(https://github.com/bevyengine/bevy/workflows/iOS%20cron%20CI/badge.svg)
is not available anymore

README.md

@@ -4,7 +4,6 @@
 [![MIT/Apache 2.0](https://img.shields.io/badge/license-MIT%2FApache-blue.svg)](https://github.com/bevyengine/bevy#license)
 [![Crates.io](https://img.shields.io/crates/d/bevy.svg)](https://crates.io/crates/bevy)
 [![Rust](https://github.com/bevyengine/bevy/workflows/CI/badge.svg)](https://github.com/bevyengine/bevy/actions)
-![iOS cron CI](https://github.com/bevyengine/bevy/workflows/iOS%20cron%20CI/badge.svg)
 [![Discord](https://img.shields.io/discord/691052431525675048.svg?label=&logo=discord&logoColor=ffffff&color=7389D8&labelColor=6A7EC2)](https://discord.gg/bevy)
 
 ## What is Bevy?